Device for withdrawing sewn workpieces from a sewing machine

ABSTRACT

A device for withdrawing sewn workpieces from a sewing machine comprising a rotatable roll having a nonslipping coating. The device is carried by a pneumatic motor arranged within the roll and carried by a tubular rod. Control means are provided for lifting and lowering the roll, to bring it in contact with the workpiece and to admit the pneumatic motor to drive the roll for withdrawing the sewn workpiece.

United States Patent Hagemeyer et al.

[15] 3,656,442 [451 Apr. 18, 1972 [54] DEVICE FOR WITHDRAWING SEWN WORKPIECES FROM A SEWING MACHINE [72] Inventors: Gunther Hagemeyer, Leopoldshohe;

Eberhardt Hennig, Bielefeld, both of Germany [73] Assignee: Kochs Adlernahmaschinen Werke AG,

Bielefeld, Germany [22] Filed: Apr. 21,1970

[2i] Appl. No.: 30,511

[52] US. Cl ..l12/214 [51] Int. Cl. ..D05b 27/10 [58] Field oiSearch ..ll2/2l4,21l

[56] References Cited UNITED STATES PATENTS 2,704,988 3/1955 Rosenbloom ..1 12/214 X 3,104,639 9/1963 Reeber ..l l2/2l4 Primary Examiner-Patrick D. Lawson Attorney-Jacob L. Kollin [57] ABSTRACT A device for withdrawing sewn workpieces from a sewing machine comprising a rotatable roll having a nonslipping coating. The device is carried by a pneumatic motor arranged within the roll and carried by a tubular rod. Control means are provided for lifting and lowering the roll, to bring it in contact with the workpiece and to admit the pneumatic motor to drive the roll for withdrawing the sewn workpiece.

5 Claims, 3 Drawing Figures DEVICE FOR WITHDRAWING SEWN WORKPIECES FROM A SEWING MACHINE BACKGROUND OF THE INVENTION This invention relates generally to an auxilliary device for use with sewing machines and particularly to a device for withdrawing sewn workpieces or workpiece cuts from a sewing machine or a sewing device.

It is already known to provide sewing equipments with devices for withdrawing sewn workpieces from workpiece clamping plates. Such a device is described in German patent 1.213.713. In this known device the workpieces are pushed out of the opened workpiece holders by means of a compressed air stream. When using this device, the motor is under the influence of an airstream which arises after each lifting of the workpiece holders and is troublesome.

There are further known mechanical devices for withdrawing workpieces from workpiece holders of sewing devices, for instance from the German Utility Pat. No. 1.985.844. However, these known devices are too slow for use with a sewing device in which the insertion and withdrawal of the workpieces take place at the same place.

Finally, there is already known a device which is provided with a roll having a nonslipping coating and which is lowered upon the workpiece and is then rotated by means of' an air cylinder via a rope wound onto the roll to draw the workpiece out of the workpiece holder. A torsion spring arranged within the roll and tensioned during the rotation of the roll draws the rope back upon the roll after the latter is lifted. It has been found that in this device the thin rope breaks within a relatively short period of operation. This also applies to the torsion spring, which is made of thin band steel.

It is the primary object of this invention to provide a device of the above mentioned character in which these deficiencies are eliminated.

It is also an object of the present invention toprovide such device of the above character which is capable of withdrawing pieces or workpiece cuts from a sewing machine in a quick manner.

It is another object of this invention to provide a device of the above character which can be attached to conventional sewing machines and to automatic sewing devices.

The above and other objects of the invention are set forth in the appended claims and are disclosed in the description given by way of example of the embodiment illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial plan view showing a sewing device provided with the device for withdrawing sewn workpieces;

FIG. 2 is a side elevational view corresponding to FIG. 1, and

FIG. 3 is a fragmentary sectional view taken along line 111 III of FIG. 2 on an enlarged scale.

DESCRIPTION OF THE PREFERRED EMBODIMENT In a sewing device comprising a sewing machine 1, there is arranged a work surface 2 which is movably controlled in a horizontal plane under the needle of the sewing machine 1. Two bearing blocks 3 are fastened to the workpiece surface 2, for receiving a shaft 4, about which are pivotally mounted two arms 5. A workpiece clamping plate 6 is'fastened to the arms and serves for clamping a workpiece 7. A block 8 is pivotally mounted about the shaft 4, in which is displaceably a tubular rod 9 clamped. At its angled end the tubular rod 9 is provided with a thread 10 (FIG. 3) into which is screwed a small pneumatic motor 11, of appropriate size, as for instance used in pneumatic drill machines. Screwed on the drive shaft 12 of the pneumatic motor is a cup-shaped roll 13, the side wall 14 of which surrounds the pneumatic motor 11. A helically extending and nonslipping coat 15 is cemented to the cylindrical surface of the roll. The material may be loom beam coating.

Linked to the tubular rod 9 and the work surface 2 is an air cylinder 16 (FIG. 2) which serves for lifting the tubular rod 9 together with the roll 13.

A lever 17, provided with a cam 18, is pivotally mounted on the arm 5 for cooperating with animpulse air valve 19. This impulse air valve 19, of known size, operates in such a manner that it will be only actuated when the workpiece clamping plate 6 is in a raised position. The impulse air valve 19 is arranged between the tubular rod 9, serving as a delivery conduit for compressed air to the pneumatic motor 11, from the compressed air supply and serves for the momentary admission of compressed air of the pneumatic motor 11. A threeway air valve 20, controlling the air cylinder 16, is likewise arranged in the effective range of the lever 17.

The operation of the device is as follows:

In the normal position of the sewing device the clamping plate 6 and the tubular rod 9 with the roll 13 are in a raised position. In this position the air cylinder 16 is under the pressure of air flowing through the air valve 20 (FIG. 2). The plunger 21 of which is in the lower position which is caused by the lever 17. After insertion of a workpiece 7, the plate 6 fastened to the arms 5 which are pivoted about the shaft 4, is lowered upon the workpiece 7, whereupon the lever 17 which is hinged to the arm 5, moves into the dotted drawn position, and the plunger 21 being under the tension of a spring (not shown) closes the delivery pipe. By this, the air cylinder 16 will be discharged at which the air escapes from a vent 22 in the air valve 20. Now, the tubular rod 9 will be lowered until the roll 13 comes into contact with the workpiece 7.

During the lifting of the lever 17 the cam 18 being a part of the lever 17, actuates the roll 23 of the impulse air valve 19 but turns the roll 23 against the action of a not shown spring out of the normal position into a dotted drawn position without actuating the impulse air valve 19. After reaching the dotted drawn position of the lever 17 the roll 23 goes back into the normal position.

After the termination of the sewing operation the workpiece clamping plate 6 will be lifted and the lever 17 will be lowered, so that the cam 18 of the lever 17 actuates the gate valve 24 against the tension of a not shown spring via the roll 23 of the 'impulseair valve 19. By this, a comparatively short air impulse is given through the bore 25 in the gate valve 24 to the pneumatic motor 11 which causes the roll 13 to rotate at a high speed, and consequently the workpiece 7 will be removed from the sewing device with a relatively high speed. Before the clamping plate 6 arrives in the highest position the lever 17 actuates the air valve 20, whereby the compressed air can flow through the valve 20 to the air cylinder 16 for the purpose of lifting the tubular rod 9 and also the roll 13.

What we claim is 1. In combination with a sewing device having a sewing machine, a work surface and a liftable workpiece clamping plate, means for withdrawing sewn workpieces from said liftable workpiece clamping plate, comprising a rotatable roll having a cylindrical surface provided with a non-slipping coat surrounding said cylindrical surface and shaped as a cup, a pneumatic motor received in said cup-shaped roll for driving said roll, an angularly ended tubular rod threaded at both ends for carrying said pneumatic motor on its angled end and serving as a delivery pipe for compressed air to said pneumatic motor, said tubular rod being swingably fastened to said work surface of said sewing machine, an air cylinder between said tubular rod and said work surface for removing said roll from said workpiece, and control means actuated by said workpiece clamping plate for momentarily admitting air to said pneumatic motor during the lifting of said workpiece clamping plate, for admitting air to said air cylinder after lifting said workpiece clamping plate and for blocking the admission of air to said pneumatic motor and discharging said air cylinder during lowering said workpiece clamping plate upon a workpiece.

2. The device for withdrawing sewn workpieces from said lifted workpiece clamping plate as set forth in claim 1, in

which said control means comprise an impulse air valve arranged between the compressed air supply and said tubular rod and momentarily operable only during the lifting of said workpiece clamping plate, and a three-way air valve arranged between the compressed air supply and said air cylinder for admitting air to said air cylinder after lifting said workpiece clamping plate and discharging said cylinder after lowering said clamping plate upon a workpiece.

3. In combination with a sewing machine having a work surface, means for withdrawing sewn workpieces or workpiece cuts from the sewing machine comprising a rotatable roll having a cylindrical surface, a nonslipping coat surrounding said cylindrical surface and adapted to contact said workpieces, carrier means for said roll, driving means to rotate said roll for accelerating said workpieces when leaving said sewing machine, and control means for said driving means, said driving means comprising a pneumatic motor having a driving shaft, said roll being cup-shaped for receiving said pneumatic motor within said roll, said driving shaft carrying said cupshaped roll.

4. In combination with a sewing machine having a work surface, a device for withdrawing sewn workpieces or workpiece cuts comprising a rotatable cup-shaped roll having a cylindrical surface, a nonslipping coat surrounding said cylindrical surface and adapted to contact said workpieces, a pneumatic motor received within said cup-shaped roll and having a driving shaft for carrying said cup-shaped roll, carrier means for said pneumatic motor, lifting means cooperating with said carrier means for removing said roll from said work surface, and control means for controlling said lifting means and said pneumattc motor.

5. The combination as claimed in claim 4, in which said lifting means comprises an air cylinder and said carrier consists of a tubular rod threaded at both ends for receiving said pneumatic motor and serving as a delivery pipe of compressed air to said pneumatic motor, said tubular rod being swingably secured to said work surface of said sewing machine, and said control means for controlling said air cylinder and inflow current of compressed air to said pneumatic motor comprise independent air valves actuated by said sewing machine. 

1. In combination with a sewing device having a sewing machine, a work surface and a liftable workpiece clamping plate, means for withdrawing sewn workpieces from said liftable workpiece clamping plate, comprising a rotatable roll having a cylindrical surface provided with a non-slipping coat surrounding said cylindrical surface and shaped as a cup, a pneumatic motor received in said cup-shaped roll for driving said roll, an angularly ended tuBular rod threaded at both ends for carrying said pneumatic motor on its angled end and serving as a delivery pipe for compressed air to said pneumatic motor, said tubular rod being swingably fastened to said work surface of said sewing machine, an air cylinder between said tubular rod and said work surface for removing said roll from said workpiece, and control means actuated by said workpiece clamping plate for momentarily admitting air to said pneumatic motor during the lifting of said workpiece clamping plate, for admitting air to said air cylinder after lifting said workpiece clamping plate and for blocking the admission of air to said pneumatic motor and discharging said air cylinder during lowering said workpiece clamping plate upon a workpiece.
 2. The device for withdrawing sewn workpieces from said lifted workpiece clamping plate as set forth in claim 1, in which said control means comprise an impulse air valve arranged between the compressed air supply and said tubular rod and momentarily operable only during the lifting of said workpiece clamping plate, and a three-way air valve arranged between the compressed air supply and said air cylinder for admitting air to said air cylinder after lifting said workpiece clamping plate and discharging said cylinder after lowering said clamping plate upon a workpiece.
 3. In combination with a sewing machine having a work surface, means for withdrawing sewn workpieces or workpiece cuts from the sewing machine comprising a rotatable roll having a cylindrical surface, a nonslipping coat surrounding said cylindrical surface and adapted to contact said workpieces, carrier means for said roll, driving means to rotate said roll for accelerating said workpieces when leaving said sewing machine, and control means for said driving means, said driving means comprising a pneumatic motor having a driving shaft, said roll being cup-shaped for receiving said pneumatic motor within said roll, said driving shaft carrying said cup-shaped roll.
 4. In combination with a sewing machine having a work surface, a device for withdrawing sewn workpieces or workpiece cuts comprising a rotatable cup-shaped roll having a cylindrical surface, a nonslipping coat surrounding said cylindrical surface and adapted to contact said workpieces, a pneumatic motor received within said cup-shaped roll and having a driving shaft for carrying said cup-shaped roll, carrier means for said pneumatic motor, lifting means cooperating with said carrier means for removing said roll from said work surface, and control means for controlling said lifting means and said pneumatic motor.
 5. The combination as claimed in claim 4, in which said lifting means comprises an air cylinder and said carrier consists of a tubular rod threaded at both ends for receiving said pneumatic motor and serving as a delivery pipe of compressed air to said pneumatic motor, said tubular rod being swingably secured to said work surface of said sewing machine, and said control means for controlling said air cylinder and inflow current of compressed air to said pneumatic motor comprise independent air valves actuated by said sewing machine. 